1. Field of the Invention
The invention relates to a method for joining a rod-shaped heating element with a tubular carrier element, and a rod glow plug which includes a rod-shaped heating element in a tubular glow plug body.
2. Description of Related Art
Rod-shaped heating elements which are supported in tubular carrier elements are known. One of the best known examples of a rod-shaped heating element is a glow plug which includes a rod-shaped glow pencil is supported in a tubular glow plug body.
When joining a glow pencil and a glow plug body, the glow pencil is pressed or inserted into the glow plug body. In such a case, only materials which exhibit sufficient deformability and non-deformability for such a pressing-in operation can be used. For pressing-in the heating element, certain component lengths, especially of the glow pencil, should not be exceeded in order to avoid buckling of this component during the pressing-in operation. Furthermore, grooves can arise during pressing-in, which lead to looseness between the glow pencil and the glow plug body.
The object of the present invention is to provide a method of joining a rod-shaped heating element with a tubular carrier element so as to overcome the aforementioned disadvantageous effects that occur with the pressing-in of the heating element into the carrier element. At the same time, the method in accordance with the present invention does not require a certain component length in order to avoid the buckling of the component. In this regard, a ceramic rod-shaped heating element may be used in order to be easily joined with metal carrier elements without the aforementioned groove formation occurring.
The aforementioned problems are solved in accordance with the present invention by providing a method of joining a rod-shaped heating element with a tubular carrier element whereby a cylindrical carrier ring is connected to the rod-shaped heating element using magnetic forming technology, and the rod-shaped heating element and carrier element are subsequently inserted into the tubular carrier element.
An advantageous feature in accordance with the present invention is the attaching or forming of the rod-shaped heating element with a carrier ring using magnetic forming technology. The magnetic forming technology may be providing using xe2x80x9cMagnetoPulsxe2x80x9d from Magnet-Physik Dr. Steingroever GmbH of Cologne, Germany.
The present invention will be explained in greater detail with a preferred example of a glow plug with rod-shaped heating element and tubular carrier element according to the following figures, which show: